Wind driven machines have been known for centuries as a means for performing useful work, the windmills of Holland being perhaps the most notable example of utilization of wind energy for machine operation. In the past, there has been severe limitation on the development of wind driven prime movers and one of the prime limitations has been that of size, particularly in connection with the traditional horizontal rotational axis mill or machine. Another factor inhibiting the development of wind driven machines has been fragility and the inability of the machines to withstand severe storms without destruction. Other recognized problems which need not be enumerated herein have, until recently, slowed the development of wind machines nearly to a standstill.
Notwithstanding the above, the current worldwide recognition of dwindling conventional energy resources have rekindled an active interest in the development of wind driven machines with the result that quite a number of new machine configurations have come into being, at least on an experimental basis and have exhibited some improvement over the traditional prior art in terms of operational efficiency. For the most part, however, recent efforts toward advancing the art have adhered to the basic approaches used in the past with certain refinements based on recent knowledge and technology. Therefore, most of the hinderances to complete practicality extending in the past continue to exist, such as practical limitation in the size and weight of rotor arms, the necessity for too many moving parts and cyclic controls, particularly in the case of vertical axis wind machines whose rotors must simultaneously move with the wind and against the wind. The traditional horizontal axis windmill utilizing propeller-like wind driven blades is severely limited in terms of the size and weight of such blades and supporting means, as well as the fact that such a machine can only respond to winds moving in one prevailing direction. On the other hand, the advantage of the traditional horizontal axis (Dutch) windmill compared to the vertical axis machine is simplicity of construction without need for many moving parts or cyclic controls to activate wind capturing devices on one side of the vertical rotational axis while collapsing such devices on the far side of the rotational axis which moves against the wind.
For the above reasons and many others, neither the horizontal axis nor vertical axis wind driven machine has been completely practical or widely utilized except on a limited scale up to the present time, despite the recognized and urgent need for sources of energy which can at least supplement conventional sources at the present time, and also supplement the more exotic and costly energy sources of the future, which are already on the horizon, including solar and nuclear energy.
To comply with the duty to disclose known prior art under 37 C.F.R. 1.56, the following prior United States patents of some relevancy to the invention herein are made of record in this application:
2,003; 346,797; 615,782; 794,706; 1,092,458; 1,126,069; 1,539,157; 1,714,808; 1,914,426; 2,094,603; 2,518,611; 2,707,521; 3,565,546; 3,897,170; 3,920,354; 3,930,750; 3,995,170; 4,004,861; 4,039,849; 4,047,833; 4,047,834.